Although such factors are more difficult to analyze and measure than the ones being analyzed in
Quantitative Investment
Analysis, they are a crucial part of any investment! As Einstein supposedly said: "Everything that can be counted does not necessarily count; everything that counts cannot necessarily be counted."

Performing a Qualitative Investment Analysis

To perform a QIA, first make a list of all qualitative factors. The next step could be to split them up in factors having a positive effect (they add value) and which ones have a negative effect (they decrease value), after which you can rank all factors by their relative importance, using symbols (++, +, 0, -, --), or some number (0-9), or even smiley's (from very happy to very unhappy).